Electronically controlled stage lighting system

ABSTRACT

A lighting system operating using a digital mirror as its operative device. The digital mirror is used to shape the light which is a passed through advanced optical devices in order to produce an output.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation application of and claimspriority to U.S. application Ser. No. 09/577,428, filed May 22, 2000,which is a divisional of U.S. application Ser. No. 08/854,353, filed May12, 1997.

FIELD

[0002] The present disclosure relates to an electronically controlledstage lighting system. More specifically, the present inventiondescribes a digital stage lighting system operating using a digitalmirror array as part of its beam forming equipment.

BACKGROUND

[0003] Stage lighting systems have increased greatly in complexity inrecent years. The current generation of stage lighting equipment useshighly sophisticated computer based control to allow a myriad display ofprogrammable and controllable special effects.

[0004] One of the more sophisticated devices is the ICON(TM) devicemanufactured by LIGHT & SOUND DESIGN(TM). The ICON(TM) includes anextremely sophisticated console from which the countless special effectscan be commanded. The console provides commands to each of the lamps inthe system. These commands select various functions at specific timeswhich are preset during the planning of an event.

[0005] The ICON(TM) units are moving lights which can be controlled tomove in at least two directions: pan and tilt. Some applications mayallow the lights to move in a third direction as well. These lights arealso remotely controllable and programmable to allow for differentlighting effects, including color, color fade, split color, “gobo”(shape of a pattern being displayed), iris, focus and others.

[0006] Moving lights such as the ICON(TM) are among the mostsophisticated units in use today. However, less sophisticated, but stillhighly complicated and computer controlled units also exist. An exampleis the WASHLIGHT(TM), available from LIGHT & SOUND DESIGN(TM). Thesecomputer controlled devices allow a limited set of effects, but at areduced cost.

[0007] All of these devices require consideration of complicated tradeoffs between various factors which influence the final feature set. Thelights need to be small in size, quiet and rugged, to accommodate theneed for easy set up, transportation, and use. They need to berelatively inexpensive to allow many lights to be used in a show.

[0008] Even though small, the lights must be capable of outputting largeamounts of light in order to illuminate the desired scene properly. Atypical minimum light output is around 5000 lumens. The residual heatfrom such a lighting operation must be effectively dissipated to avoiddamage to the control systems.

[0009] The difficult working environment requires careful monitoring andservicing of the components. However, the market continues to demandeven more features, which will lead to even further complexity andfurther demands on the system.

[0010] The inventors of the present invention have recognized a numberof issues which plague many of these lights. A first issue regards theflexibility. Previous lights have been digitally controlled, in thesense that the control occurs from and via the main console, which istypically a computer. However, many operations use only a preset numberof effects. For example, the “gobo”, which is the device that is used toshape the light being passed, is typically a discretely-selectabledevice. One or more of the gobos can be used at any time; however therehas been no way to select a gobo function other than the preselectedgobo shapes. Similarly, the colors were often selected from a colorwheel which allows only discrete colors.

[0011] Another problem is maintenance. The lights are transported andoperated by “roadies”, road-trained technicians whose main objective isto service the lights. The important issue in road shows is properoperation. Therefore, the often emergency nature of such servicingresults in many of these service operations to be done by whatever meansare necessary, with minimal documentation of the maintenance that wasperformed. This results in incomplete information about the servicing.

[0012] Moreover, the artists are often interested in new effects. Eachnew effect adds further complexity to the system and control.

[0013] Yet another problem is that the luminaires must operate reliably.However, as described above, use of a digital light shape alteringdevice is carried out with large calculation loads. It is necessary tomaintain reliable operation in such a situation. These objectives andmany others are addressed by the present invention as described herein.

SUMMARY OF THE INVENTION

[0014] A number of aspects are described according to the presentinvention and the following summary summarizes many of these aspects.

[0015] A first aspect of the invention is to enable a digital control ofmany aspects of the light beam. This uses a digital mirror device andconfiguration as described in our co-pending U.S. patent applicationSer. No. 08/598,077, the disclosure of which is incorporated byreference herewith. The techniques described in this applicationdescribe not only the use of the digital mirror, but also the techniqueswhich have been found by the inventors to enable its operation in thedesired way.

[0016] Another aspect of the invention is the provision of automatedsystems for determining maintenance information. These automated systemsallow automatic logging of events that have been done to the lamp.

[0017] Another aspect of the invention uses three different coloringtechniques, including a custom color wheel, a continuous color crossfader and an RGB wheel to allow different coloring options.

[0018] Yet another aspect of the invention involves special electronicswhich enable this new and sophisticated system to be used in a way thatemulates the previous systems.

[0019] Yet another aspect of the invention is the redundancy of thissystem. According to this aspect, special architecture is used todistribute the processing in a way that maximizes the availablecapability of operations, but yet minimizes the possibility of amisoperation or failure.

[0020] Yet another aspect is the description of an advanced coolingsystem which allows the complicated electronics to be isolated from theheat source in a new way.

[0021] Other features of this system include the following:

[0022] An improved optical path and cooling of the components in theoptical path.

[0023] A special lens system which allows better determination of thescene on the stage being imaged.

[0024] A balancing element for the moving optics so that any movingoptics do not upset the balance of the luminaire.

[0025] A remoted element for the digital mirror so that the digitalmirror can be properly located relative to the optical system,independent of the placement of the control for the digital mirror.

[0026] A special technician port which allows monitoring of status andcontrol of individual lamps.

[0027] Special systems allowing control of color changing and crossfading.

[0028] A modular architecture with each board in the system includingits own digital signal processor.

[0029] A special calibration system for the structure on each subsystemthat maintains the hardware of the subsystem married to the control onthe subsystem to allow more accurate control.

[0030] Use of up to three color changing elements: a first colorchanging element at an out of focus position, a second color changingelement at an in focus position and an RGB wheel also at an out of focusposition.

[0031] Use of cold mirrors to minimize heat transfer to the digitalmirror.

[0032] Use of the digital hardware to emulate previous generations,including emulation of a hardware gobo.

[0033] Special cooling system including a wall of air which is used bothas a heat barrier and as a source of cool air.

[0034] Special techniques for optimized use of the digital mirror.

[0035] A special motor control bus and details of its architecture.

[0036] A supervisor automatically maintaining a registry of parts whichare changed, and important system events, such as lamp life,overtemperatures, and other things.

BRIEF DESCRIPTION OF THE DRAWING

[0037] All of these aspects, and others, will be described in detailherein with reference to the accompanying drawings wherein

[0038]FIG. 1 shows a block diagram of the Medusa system;

[0039]FIG. 2 shows a block diagram of the electronic control subsystem;

[0040]FIG. 2A shows a block diagram of a second embodiment of theelectronics, showing the use of a separate processor and DSP;

[0041]FIG. 3 shows a block diagram of the system optics;

[0042]FIG. 3A shows a detail of the retroreflector;

[0043]FIG. 3B shows details of the optical system;

[0044]FIG. 4 shows a motor control subassembly;

[0045]FIG. 4A shows a flowchart of operation of the motor controlsubassembly;

[0046]FIG. 5 shows a moving balance device for a moving optical element;

[0047]FIG. 6 shows an alternative embodiment for the moving opticalelement balancing device;

[0048]FIG. 7 shows a block diagram of the controller used according tothe present invention;

[0049]FIGS. 8 and 9 are diagrams of the cooling system of the presentsystem;

[0050]FIG. 10 shows a diagram of the hand held infra red tech portcommanding device;

[0051]FIG. 10A shows a flowchart of operation of that device;

[0052]FIG. 11 shows a flowchart of the operation of the masterprocessing device;

[0053]FIG. 11A shows a flowchart of using the master to simulate ahardware gobo;

[0054]FIG. 12 shows a flowchart of operation of the supervisor;

[0055] FIGS. 13-15 show timing charts which show the timing ofoperations on the motor control bus; and

[0056]FIG. 16 shows the remoted interface board for the DMD.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057]FIG. 1 shows a basic block diagram of the system of the presentinvention, titled the “Medusa”. All operations of the system arecontrolled by console 100. Console 100 may be an ICON(TM) console whichproduces commands for lighting systems as well known in the art. Console100 produces serial lighting control data over line 102. The data istransmitted to the lighting unit 104 as well as to others shown as 106.There can be any number of such other lighting fixtures 106, however itis most likely that the number of such lighting fixtures be between 10and 400. An alternative embodiment uses a DMX based control system.

[0058] Each lighting fixture 104 includes a self-contained processingunit, including electronic, optical, cooling and mechanical subsystemsas described herein.

[0059] The optical subsystem carries out the primary function ofproducing the optical light output in a desired form. This includes thelenses and other optical elements to form the optical output. Theoptical subsystem is shown and described with reference to FIG. 3.

[0060] The mechanical subsystem controls movement of various elements aspart of the system. This includes, for example, pan and tilt movement ofthe lamp beam,-beam size, color and other similar parameters. Themechanical subsystem is effected by the subassemblies shown in FIG. 4.Each of these units includes a digital signal processor (“DSP”), amotor, and a connection to a driven element or the driven elementitself.

[0061] The electronic subsystem shown in FIG. 2 carries out control ofthe overall lamp unit, including receipt of commands from the consoleportions, monitoring and fault functions, and other electronicallycontrolled elements.

[0062] The cooling subsystem shown in FIGS. 8 and 9 maintains the propertemperature of the unit and especially the heat sensitive portions ofthe unit.

[0063] The lamp 104 as shown includes an optical system formed of anilluminating lamp 110 providing light to an optical pathway 112. Theoptical pathway 112 includes the light beam from light source 110. Lightis reflected by a cold mirror assembly including cold mirrors 114 and118. Color changing mechanism 116 is located in the fold between thecold mirrors 114 and 118. The light is colored by color changingmechanism 116, and is then passed to another cold mirror 118. Thereflected light is coupled to a light shape altering device which altersthe shape of the light beam. That device is preferably a digital mirror120 of the type available from Texas Instruments. The digital mirror isdescribed, for example, in U.S. Pat. No. 5,061,049, the disclosure ofwhich is herewith incorporated by reference to the extent necessary forunderstanding of the present invention. Use of the digital mirror isalso described in our co-pending U.S. patent application Ser. No.08/598,077.

[0064] In sum, the digital mirror is formed of an array of pixels, eachof which represents a portion of light that can be selectively passed tothe target or reflected away in some other direction. The portions ofthe light are passed to different areas: first area 122 which includes alight sink to absorb the unwanted part of the light, and a second,desired area 124 which is the location for the desired light. Thedesired light is collected by focusing optics 126 and directed towardstarget 130, usually the stage.

[0065] The optical system is controlled by the controlling structure140. Controlling structure 140 receives the serial command stream fromthe console command line 102. Other commands can alternately be inputvia a technician (“tech”) command port 142.

[0066]FIG. 2 shows a more detailed diagram of the electronics subsystem.Serial data from the console is received into a dual port serialcontroller device 210. The serial data is input directly to the masterdigital signal processor (“DSP”) 212, which is preferably a TexasInstruments multimedia video processor (“MVP”) model number TMS320C80.Master DSP 212 uses SCC 210 to provide a serial port output which isconverted to RS-485 protocol by bus driver 250. This forms a motorcontrol bus 214 which controls all of the motor subsystems 220-226within the lamp.

[0067] The motor control bus is preferably an RS485 bus which controlsand communicates with each of the motor subsystems as described hereinwith reference to FIGS. 13-15.

[0068] Each of the motor control subsystems 220, 222, 224 and 226 is aseparated unit including all of the hardware necessary to control itsassociated motor and other hardware according to applied commands. Themotor control subsystem includes a dedicated control structure. Forexample, a pan/tilt motor subsystem includes all controlling structurefor the motor, and the motor itself. This combination allows a modularoperation, precise matching between components, and more accuratecalibration.

[0069] Each motor controller carries out various functions in the lamp.Color changing controller is a motor control structure which carries outoperations to move the appropriate motors to drive the color changer forthe light. Other stepper motors 222 and 224 are provided to control themovement of movable motor devices, for example, pan and tilt motors. Thecolor motor control system 226 controls a motor to move the colorchanging element into and out of the path of the light beam.

[0070] Master DSP 212 has primary responsibility for controllingoperations of the lamp including control of the digital mirror. Thislatter operation requires computation of complex operations to providecontrol information for the digital mirror. At times, these calculationsleave little time for the master to do much else.

[0071] A separate supervisor system 230 has primary responsibility formonitoring status of the lamp and making decisions based on that status.Supervisor 230 is also connected to the motor control bus. Supervisor230 is preferably a microcontroller as described herein. Themicrocontroller monitors status of the subsystems including the master.The microcontroller can also control the motor control bus when thedetermined status makes that appear it becomes desirable or necessary.

[0072] Unlike digital signal processor 212, however, the microcontrolleris a very technically simple device, adapted for watching the bus andother devices, and monitoring for errors. The microcontroller carriesout minimal number crunching; its primary function is to protect anddiagnose faults. The supervisor also controls various other functions inthe system.

[0073] The supervisor 230 monitors the output of temperature sensors 232to monitor and control various temperatures within the system.Supervisor 230 is also connected to ballast 234 to monitor the conditionand operation of the ballast. Finally, supervisor 230 receives possibleprogram parameters from flash memory unit 236.

[0074] Light shape altering device 120 is shown as including a digitalmirror interface 238 connected to a digital mirror device 240.

[0075] The operation of the digital mirror is controlled by master DSP212 to form any light shape which can be described as a plurality ofpixels. A library of possible shapes is stored in image memory 245.These shapes are predefined. Other shapes can be dynamically obtained byframe grabber 248. The frame grabber 248 preferably receives informationfrom a video source or some digital source, and converts those shapes toa form that can be used to alter the shape of the projected light beam.

[0076] Two different embodiments of the electronics will be describedherein. A first embodiment uses the basic structure shown in FIG. 2. Themain CPU and DSP function are the same—the Texas Instrument MVP DSP,which is programmable to carry out many different desired functions. Ofcourse, other processors could be used for this function, including butnot limited to the Motorola 68000, a processor from the Intel X86series, or any other programmable CPU.

[0077] Dual port serial communication controller 210 receives serialdata 102 from the console. The DSP master 212 also uses an associatedworking RAM 213 which stores the data.

[0078] The output of DSP 212 is driven by driver 250 to form the motorcontrol bus 214 (“MCB”) via the serial communication controller (“SCC”)210. SCC includes two UARTs; one of which handles incoming communicationfrom the console, and the other of which produces a serial outputstream. That output stream forms a motor control bus (“MCB”). Bus driver250 produces an RS-485 output in the MCB protocol which is describedwith reference to FIGS. 13-15.

[0079] SCC also provides information to the DSP 212, which receives theinformation from the console, translates the information, andappropriately outputs the information.

[0080] The serial communications device 210 can also be a dual port RAMwith a mailbox. In this case, the information is set into the ram, andis flagged. The DSP 212 monitors for new data by investigating the flagto determine whether the flag is set. Whenever the flag is set, DSP 212retrieves the new information from the RAM and appropriately processesit.

[0081] The master operations are shown in further detail in theflowchart of FIG. 11. The flowchart is shown depicted instances ofoperations, each of which are preferably interrupt driven. However, theinstances could also be sequential based on a loop operation, or drivenby flag operation.

[0082] On initial power up at step 1100, the master is booted at step1102. This boot operation causes the program which is to be run by themaster to be transferred from flash memory into the master working RAM.This begins a new routine with entry of the current time t at step 1103.

[0083] A new image/operation occurs at every interval of the refreshrate, preferably every 1/60 second. The time t is used to determine whenthis time has elapsed. The master checks the flag in SCC 210 at step1104, to determine if any commands have been sent from the consoleindicating communication with that lamp. If so, the command is receivedat step 1106, and investigated to determine its contents.

[0084] Many of the commands will be lamp move/color change commands,which are similar to those commands that are executed in the prior art.Element 1108 generically calls these movement commands, covering thenon-DMD authorizing commands. Those commands are translated by themaster DSP 212 into information indicative of commands that are sent tothe slave processing boards 220-226 over the motor control bus 214.These commands include color change by cross fader, color change bydichroic color wheel, and color change by RGB wheel, lamp move commandswhich can be parsed as move to position x, y, and begin either now or attime z and be there at time t, and others. These commands are translatedand placed on the motor control bus 214 to appropriately control theassociated motors. Those commands are complete when sent—the DSP in theslave motor control subassembly processes the function.

[0085] Step 1110 shows digital mirror device controlling commands. Thesecommands include gobo shape, which shapes the light beam according to apredefined shape, and grab shape which shapes the light beam accordingto an acquired shape, which can be a shape which is downloaded to thelamp or an image acquired from a video source. A frame grabber, whichfeeds into the DSP, can also be used in order to form adynamically-changing spotlight shape which follows the shape of theperformer on the stage, and hence forms a shadowless follow spot.

[0086] Another DMD shape is iris, which corresponds to a superimpositionof two different shapes. The iris effect is simulated by commanding thedigital signal processor to superimpose an iris shape over the basicshape being displayed.

[0087] Another DMD function is the superimposition of any two differentshapes or images together to form a resultant image.

[0088] Yet another DMD effect is dim. Dimming is done by either turningoff a certain percentage of the DMD pixels in order to simulate a dimmerimage (e.g., every other pixel), or duty cycle modulating those pixels(alternatively turning them on and off) faster than the eyes' capabilityof seeing this movement.

[0089] Another possible DMD effect is the simulation of a beam fielddistribution or profile, e.g., a cosine shaped profile for thespotlight. The inventors recognized that spotlights are often overlappedwith other spotlights at their edges. The area of overlap can cause abright spot at those edges. The DMD is used to form a spotlight withedge portions that have intensities that are lower than the intensity inthe center of the beam. The rate of intensity drop off is preferably acosine function. In this way, when the two edge portions of twospotlights are placed one over the other, the overlap does not appear tobe overly bright. However, such variable profiles will not be desired inall situations. A variable brightness profile will be desired insituations where multiple beams will be overlapping at their edges.However, other effects, such as illuminating a gobo, will be betterilluminated using flat intensity profiles.

[0090] The DMD can be electronically addressed to allow electronicallychanging electronically changing between these intensity profiles,albeit at the cost of loss of brightness.

[0091] Other DMD commands are described in our co-pending U.S. patentapplication No. 08/598,077. These effects include, but are not limitedto, strobe, flower strobe and others.

[0092] The gobo effect can simulate a rotating gobo. This requires theDSP to begin with the image at point x, and rotate the image in aspecified direction at a specified speed. The DSP operates at eachperiod of the refresh rate of the image, e.g., each 1/60 of a second, tocalculate the new rotated shape. That shape is used to alter thereflectivity of the pixels of the digital mirror.

[0093] In any of these cases, the DSP is instructed to form an image. Inthe case of a moving image, the next image is formed during the nextcalculation cycle, e.g. 1/60 second later. Depending on the goborotating speed, the image may have incrementally changed position, ornot changed position at all.

[0094] At step 1112 the DSP operates to carry out the applied commands.

[0095] If there has been no input from the console at 1104, the signalprocessor checks at step 1120 to determine if a previously processedcommand is still in process. If so, the next processing operation, e.g.the next image calculation, is carried out at step 1122.

[0096] The master therefore assigns top priority to calculation oflighting and effects functions. After all of these functions have beencarried out, the system operation commands are detected at step 1130. Atstep 1132 the DSP checks to determine if it has any requests from thesupervisor, and if so evaluates that request. The request from thesupervisor can range from shutdown entirely to request for the mastercontroller to relinquish control of any of the subsystems.

[0097] At step 1140 the master carries out the miscellaneous functions,which can include responding to requests for status, checking the statusof various system functions, a self check, and the like.

[0098] At step 1142 the processor waits for its next 1/60 of a secondinterval=t+1/60s at which time the next image needs to be processed.

[0099] Each image, once calculated, is placed into frame buffer 213,which is for example a dual port video memory. Placement of a new imageinto memory 213 causes the previous image to be sent to the digitalmirror 240 via its interface 238. This hardware effects a doublebuffering operation which effectively enables the DSP to continuecalculating the next image in the sequence while the previous image isbeing displayed.

[0100] Notice again that the master processor is primarily concernedwith calculation of the proper parameters to allow the lighting effectto be properly carried out. The master processor is only secondarilyconcerned with system status.

[0101] There can be two separate processors operating the system—themaster processor and DSP. The preferred embodiment uses the MVP whichcarries out the functions of both the processing and digital signalprocessing.

[0102] A second embodiment uses a separate processor and MVP as shown inFIG. 2A. In this case, the master processor is a 68000 CPU 250. CPU 250holds the DSP 212 in reset until the output power is stabilized. Afterthe power has stabilized, the CPU 250 provides a boot sequence for theDSP 212. This usually is done by moving a boot program from memory 252to the dual port RAM 254, setting a flag, and then releasing the DSP 212from reset. The DSP 212 boots from the dual port RAM 254 and loads thatinformation into its own memory. The DSP 212 then operates based onapplied instructions.

[0103] As described above, an important part of this system is itsability to emulate previous lamp generations. Previous systems creatednew generations of lamps which required the lighting designers to make achoice between the old lamp generation with its now-limited feature set,or the new feature set; possibly requiring reprogramming of every effectin the entire show. The latter may constitute a formidable task.

[0104] An important feature of the new system of the present inventionis its ability to emulate previous lamp generations. This allows theprevious programs to be used and possibly modified to add improvedfeatures. The subsystems that are susceptible of emulation include atleast the color selection, gobo, iris, focus, and movement.

[0105] The digital mirror device 240 shapes the output light beam.Therefore, proper control of the digital mirror enables control to forma substantial number of different shapes.

[0106] Emulation of the previous generation of hardware gobo systemsrequires determination and use of the shapes of the hardware gobos asshown in the flowchart of FIG. 11A. The inventors formulated this as aproblem of how to project a relatively simple graphical picture. Eachgobo in the previous gobo set is represented by a picture at step 1142.Each picture is translated to a graphical representation, e.g. a bitmapof the pixel area, at 1144. That graphical representation is used tocommand the digital mirror at step 1146. Therefore, each gobo in theprevious generation gobo set is translated to a digital mirror commandset that emulates the hardware gobo.

[0107] The actual output to the digital mirror device is in aproprietary format specified by Texas Instruments, the manufacturer ofthe digital mirror device. Texas Instruments' interface board accepts asequence of binary values, each corresponding to an intensity of thepixel on the DMD. The interface board converts that sequence to itsproprietary format.

[0108] The inventors recognized that information storage in this DMDsystem is a serious issue. For an image of 1280 by 1024 pixels, theimage itself is formed of 140,000_(HEX) which equals approximately1,310,720 pixels. A 1024 pixel circle is formed by 823,550 pixels. Theaverage image hence uses somewhere between 800,000 and 1.3 millionpixels. Storage of such graphical pictures takes a large amount ofstorage space. The files are preferably stored in some compressed form;more preferably as a vector representation of the file. The preferredstorage formats include HPGL and DXF formats. However, any format whichrepresents a shape by a format which is compressed relative to a bitmapis preferred.

[0109] Projection of a stored gobo is accomplished by reading out thevector representation, converting the vector representation to a pixelbased output such as a bitmap (step 1144), and commanding the digitalmirror using the bitmap file (step 1146).

[0110] The emulation technique therefore converts this information intoan emulation of a hardware gobo. This hardware gobo can be exactly whatis found in the previous lamp generations such as the ICON (TM). Use ofthe RGB wheel synchronized with the digital mirror commands also allowsthe gobos to be projected in any desired combinations of multiplecolors. However, use of the RGB wheel requires dividing the system intomultiple frame portions. Hence, the image intensity will accordinglydegrade.

[0111] Another issue in the DMD is caused by its lack of persistence.Since the DMD has no persistence, images cannot be formed by building uptwo sets of alternate lines of the image, as is frequently done in videoprojection. Accordingly, the system displays an entire image at each onetime. Double buffering is used. One image as produced is stored in VRAMwhich the next image is being calculated.

[0112] Each of these images uses on the order of a million pixels foreach image. Hence a million pixels need to be calculated for each imageoperation.

[0113] Manipulation of the image is similarly complex. The ICON(TM)system uses a hardware gobo which can be rotated by motor and drivesystem. This simple operation is simulated in the Medusa by calculatingeach rotated position in FIG. 11 each interval of the refresh rate atstep 1142. The calculation of a million pixels in 1/60 of a second, forexample, however, requires that a matrix multiplication be carried outin 20 ns.

[0114] The TI MVP has the capability of making those calculations inthat time. However, this leaves only minimal time for monitoring theremainder of the system. This system uses a supervisor unit forredundant monitoring operation so that the system is properly monitoredno matter how large the calculation load.

[0115] In contrast to the master DSP 212, the supervisor 230 isprimarily a system status determination unit. The supervisor 230 carriesout a number of functions, including primarily detecting whether thesystem, including the master DSP 212, is operating properly. Thesupervisor 230 also carries out a number of secondary functions,including logging a registry of events and faults, igniting and dousingthe bulb, control of fan speed, and responding to user requests forstatus.

[0116] A block diagram of the supervisor unit 230 is found in FIG. 7.

[0117] A first connector 710 includes various system monitoring inputs.Connector 710 receives inputs from many of the sensors which sense theparameter values in the system. This includes the temperature at themain bulb which forms the main lighting source for this system, and thetemperature at the digital mirror device. The power supply may beseparately sensed by a power supply sensor, e.g., of the I²C type. Theseand other inputs are multiplexed into a stream by communication device712. The information forms stream 714 which is coupled tomicrocontroller 716. The microcontroller 716 is preferably an ATMELAT89S8252.

[0118] The inputs to the controller 716 represent many of the parameterswhich can be monitored by the system.

[0119] The sensor block 710 includes those sensors known as theproduction sensors. These devices will be used in all units which areeventually made. A second set of inputs 720 are called the developmentsensors. These sensors will be monitored during development but mightnot be used in the actual production device. The development sensorsinclude a number of test temperatures at various places within the unit,including power supply temperature, ballast temperature, casetemperature and temperature at motors. The development sensor output 722is multiplexed and sent to microcontroller 716.

[0120] The ballast monitoring section 730 connects directly with theballast 732, which drives lamp 734. The ballast is preferably a solidstate type electronic switching ballast. It should be understood thatthe parameters shown in FIG. 7 are only exemplary. Outputs to theballast include ignite and power control respectively which start thelamp and control the power of the lamp. The ballast also includesparameter returns including a parameter indicating that the lamp is litand a lamp alert indicating a problem or short in the lamp, or lampdeterioration due to age.

[0121] The microcontroller 716 also communicates to tech port 740. Thetech port allows low level communication with the lamp device. Serialinformation is received from tech port by uart and presented to themicrocontroller 716 over parallel data bus 744.

[0122] The main IO connector 750 provides the main input and output tothe device. A reset system allows sending a hard reset which to each ofthe slave processing subunits in the system. This operation enables themicrocontroller to totally reset the subassembly if problems aredetermined.

[0123] The reset is effected without a dedicated reset line by using atimeout operation on the serial bus. The serial line is normally high,e.g., 5 volts, to indicate an idle state. A communication is sent bybringing the output alternately low and high. According to this system,a timeout is caused if the output signal is low for too long a time. Forexample, tmax, indicating the longest time that the signal can stay inone state without transiting, may typically be 3 byte times, e.g. 100μs. If the signal stays low for longer than 3 byte times, all hardwaremonitoring the communication is reset. The slave processing systems aretherefore reset by maintaining the signal low for longer than 3 bytetimes.

[0124] Inputs and outputs are also provided for various control featuresincluding pan and tilt, zoom, focus, color processing and the imageprocessing.

[0125] Input area 760 is a programming port which enables programming ofthe flash memory within the microcontroller 716 at manufacture or duringsoftware updates.

[0126] The watchdog supervisor unit receives a working clock of 8 MHZfor a 250 Kbaud bus; element 770. A real time clock 772 is alsoprovided. The operation of the supervisor maintains a registry ofvarious events in working memory 774.

[0127] For example, the supervisor tracks bulb life by storing anindication of bulb changing along with the current time stamp, each timea bulb is placed into service. Time stamps for other events are alsostored. The supervisor also keeps track of certain events, includingremoval of certain subsystems. It is presumed that these subsystems areserviced when removed.

[0128] Certain changes which cannot be automatically detected, such asthe time since bulb change, are manually entered into the registrythrough the tech port. This information can be obtained over theprogramming port 760 or over the tech port 740. This enablesdetermination of the life of various elements.

[0129] The information in the registry can be read by a serial deviceover tech port. An alterative embodiment allows the information to becommanded to be displayed by the lamp itself. A lamp display commandcauses the messages to be converted to fonts and used to control the DMDto display the text as a shaped light output. This allows detecting thecontents of the registry without a dedicated display terminal using theexisting digital light altering device as a display mechanism.

[0130]FIG. 12 shows a flowchart of operation of the secondarysupervisor. It should be understood that the processes are preferablyinterrupt-driven.

[0131] The supervisor begins its monitoring loop at step 1200 bycomparing the sensor outputs to thresholds. The various sensors whichare monitored are described above, and the thresholds can be adaptivelyset.

[0132] Step 1202 determines whether any of the sensor outputs areoutside of predefined limits. This detection begins an out of limitprocessing routine, of which the first step 1204 enters an entry intothe registry indicating the fault. The registry entry includes anindication of a date and time from the date stamp, as well as anindication of the problem itself. The registry is preferably maintainedin non volatile (“NV”) RAM so that the registry entry persists even whenpower is shut down.

[0133] Step 1206 determines whether the present overlimit is critical. Acritical overlimit might be a temperature which is sufficiently high,for example, that it poses a risk of fire damage or otherwise requiresshut down of the subsystem. If the present problem is over a criticallimit at step 1206, step 1208 represents a step to obtain instructionsfor the particular subsystem being monitored. For example, if the systemmonitors a temperature of 450° C. on the ballast, and this is over acritical limit, step 1208 is a step of downloading how to handle ballastovertemps. Since the ballast is such a crucial part of the lamp, it mayvery well be that this requires shutdown of the entire lamp.Alternatively, some subsystems may allow shutdown of only that subsystemwhile maintaining the rest of the lamp. Step 1210 represents followingthe instructions which were downloaded at step 1208.

[0134] In some circumstances, it may be desirable to relay a status bitto the console indicating that this critical limit has been exceeded asshown at step 1212.

[0135] The processing operation of steps 1208/1210 occurs when theparameter is detected to exceed a critical limit. If step 1206determines that the operation is not over a critical limit, then thefault is a noncritical limit by process of elimination. Step 1214represents the operation of reading the instructions that are adaptedfor a noncritical limit.

[0136] All of the noncritical limits are entered into the registry at1204. Certain noncritical limits may result in, for example,modifications to operation which may tend to allow the system to operatemore effectively. For example, if the limit is an overtemp in theballast, then the operation may carry out a noncritical limitinstruction such as reducing the ballast output by 20% or increasing theamount of cooling.

[0137] At the completion of either of these routines, control passes tostep 1220 which represents the watchdog routine. The watchdog routineoperates as a conventional watchdog. Typically, a special line isattached to the processor. The processor program includes a routine fortoggling that line periodically, e.g., every 10 μs. If there is notoggle within the preset time, then a watchdog fault is determined atstep 1220. A conventional watchdog processing routine is carried out atstep 1222. This includes entering a processor fault in the registry, andthen sending a hard reset to the master processor. If another processorfault occurs within a certain time, the system may respond by sendinganother reset to the processor or by shutdown.

[0138] Step 1230 represents detection of a communication on the motorcontrol bus. This communication is monitored at step 1232. Any necessaryaction is determined at step 1234 and is carried out at step 1236. If noaction is required, control returns to the main processing loop.

[0139] Step 1240 represents the registry update routine. The currentregistry configuration is compared with the registry of configurationdata that is stored in the nonvolatile memory. Step 1242 determines ifthere have been any changes to this configuration. If so, information iswritten to the registry including date and time of the change detectedat step 1244, and what change was detected. Processing returns to theloop to step 1250 which represents the tech port communication routine.

[0140] Step 1250 indicates that a communication on the tech port hasbeen detected. This communication can be a command of the supervisor tocarry out any of a number of functions. Step 1252 schematicallyrepresents carrying out those functions.

[0141] Step 1260 represents the sending of status to the tech port. Anew parameter is sent to the tech port each 15 seconds, to allowmonitoring of parameters.

[0142] Step 1262 represents the DMD display routine. When activated,this displays the contents of the registry and the most recentparameters on the DMD, so that projected light is projected in the shapeof the information to be displayed or its complement.

[0143] The overall system control of a lighting system has beentypically accomplished from the console. The console couples commands toeach of the commanded lamps. An alternative communication and controlscheme is made possible by the use of tech port 231 on the supervisor.The tech port is a serial I/O port which allows operation as discussedherein. In summary, the tech port allows monitoring and control of anindividual lamp via a simplified interface. As part of this monitor andcontrol, the supervisor sends a status report to the tech port at step1260.

[0144] The supervisor also has overall control over the operation. Forexample, if the temperature sensor determines that the lamp is too hot(overtemp), the lamp operation itself may be reduced or extinguished.The supervisor may hence respond by shutting off or reducing the outputof ballast 234.

[0145] The tech port communications device is preferably a wirelesscommunication system. A preferred device is a serial device 1000, e.g.,a device with a small display 1002, and an infrared communications port1004. This configuration allows the technician or other monitoringpersonnel to move from area to area with a hand held terminal. As thetechnician comes into proximity of a specific luminaire, the techniciancan monitor and control that specific luminaire.

[0146] The supervisor can be controlled itself through the tech port231. One particularly preferred embodiment provides an infraredtransceiver on the tech port which is commanded by infrared hand heldtech port supervisor 102. Preferably this uses off the shelf hardware toallow communication between the tech port and its tech port controllingdevice.

[0147] One use of the tech port is to allow the downloading ofdiagnostic information and troubleshooting aid information. Thesupervisor stores, and allows downloading via the tech port, a number ofinformation pieces which can be useful in diagnosis. One importantoperation is the history from the registry; including information aboutdifferent parts of the lamp. For instance, the supervisor monitors colorchanger status. When a color changer is removed, the supervisor maydetermine via the FIG. 12 flowchart, that the bulb has been removed. Thesupervisor stores a time stamp indicating that the bulb has beenremoved. This indicates life: how long has this device been in service.The monitoring entity can determine how likely it is that the device mayneed to be replaced. Another use for the tech port is actually duringservice. As described above, in this operation the supervisor assumesthat if a device is removed, it has been removed for replacement.However, there may be times when a service technician removes the devicefor some other reason. At those times, the service technician can usethe tech port to tell the supervisor not to reset the previous timestamp: essentially to maintain that time stamp as it was previously.

[0148] Another operation is determination when any particular item hasbeen serviced, including for example the ballast and the color filters.Servicing of the color filters or the ballast leaves a time stamp in thesupervisor indicating that these items were removed at that time.

[0149] Various places in the lamp are monitored by temperaturecontrollers as described above. Those places in the lamp can bemonitored through the infrared tech port or by direct connection to aprinter.

[0150] Another determination made by the supervisor is when asubassembly/subsystem card was last swapped out. The supervisormaintains a registry of the serial numbers of each card that are presentin the device. When a new card replaces an old card, the serial numberchanges. The supervisor hence can detect a serial number change todetermine that a card has been changed.

[0151] This solves a specific problem in the art. Road technicianstypically operate under stressful and difficult circumstances. Theinventors have found that when road technicians carry out certainoperations, it becomes difficult for them to write things down. Thisbecomes a way to relatively easily figure out many of the things theyhave done, since the supervisor automatically maintains an indication ofwhat has been done.

[0152] The infrared hand held tech port can use relatively simplesoftware such as “hyperterminal” with an infrared port. Alternately, thetech port can use relatively more complicated software as discussedpreviously which receives only certain messages which the terminaldevice needs to decode. Preferably, however, the terminal is a dumbterminal that uses no software at all.

[0153] Each specific subassembly has an assigned serial number betweenzero and 2³². Each serial number is unique to a specific card.

[0154] The subassemblies also have an address. The address is set by thespecific slot in which the assembly is placed. The address is ahard-wired 8 bit number that allows communication over the motor controlbus to any device plugged into the specified slot.

[0155] A diagram of the tech port communication device is shown in FIG.10. The operation of the tech port is described with reference to theflowchart of FIG. 10A. At step 1050 the device determines whether it isin range of a particular light. When the device comes in range, itreceives the status information, representing the significant eventswhich have occurred since the last status update. The tech port deviceis preferably a dumb terminal, but the device may alternately be apalmtop or the like. This status information may be in some compressedform if a more intelligent system is used. For example, error numberscould be communicated, and converted to textual information indicativeof the textual information.

[0156] Step 1054 represents commands being sent from the hand held techport to the tech port device. The commands shown in step 1054 includeregistry faults and take command. Other commands could of course bealternatively entered. At step 1056, the registry operation requeststhat the most recent entries in the registry be sent. At 1058, inresponse to the send faults command, the most recent faults are sent. Atstep 1060, a command is sent to the master indicating that thesupervisor requests to take control of a particular lamp.

Imaging

[0157] One important flexibility of the present system is its capabilityto form virtually any image as its gobo outline. The system can also usemany other kinds of images.

[0158] Photographic bitmaps are formed from color images, e.g. of 256colors. The color images are converted, using known techniques, intodata indicating chrominance and luminance of portions or pixels of theimages. The luminance (Y) values corresponding to the 256 colors arethen used to form an 8 bit gray scale. This allows photographic bitmapsto be scanned in and used as a gray scale gobo using the flowchartgenerally shown in FIG. 11A.

[0159] Other image operations which can be carried out by the digitalsignal processor include special functions. The DSP includes functionsallowing operations to focus, defocus, hard edge and soft edge. The DSPalso allows forming multiple superimposed images.

[0160] The DSP can calculate a resultant image as a result ofsuperimposition of any number of images upon one another. This can forma gobo outline.

[0161] Another such superimposed image superimposes an iris image on topof the image to simulate the operation of an iris.

[0162] Another such superimposed image is the use of multiple gobos,each of which operates the image. For each of these operations, thesystem requires correspondingly more calculation power.

[0163] Another DSP operation is the frame grab operation. Selection ofthe analog signal from the video grabs the frames from the appliedvideo. Each image is then digitized and displayed.

[0164] The system of the present invention uses slave processing boardsto control each motor, as shown in FIG. 4. The FIG. 4 subsystem is acolor changing system, including color crossfading discs 460 and 462. Apoint where the two discs cross forms the optical gate 464. Each of thediscs has an associated driving motor 466, 468 which drives therotational position of the discs.

[0165] The color cross fader 308 preferably uses cross fading discs ofthe type shown in our U.S. Pat. No. 5,426,276. These discs, in summary,have characteristics whereby the relative positions with respect to oneanother are changed to allow a different passband based on therelationship between the cutoff wavelengths of the two different discs.The passbands can be continuously changed to continuously change thecolor of the projected light.

[0166] The inventors have found that in practice these discs showwavelength cutoff tolerances, which are believed to be due mostly to thedichroic deposition process. These tolerances cause the start frequencyand end frequency to vary from disc to disc. The calibration operates bydetermining a start point, determining an end point, and finding alocation of a specified center point. This information is used forcalibration purposes, since it compares the specific operation of thediscs with other discs.

[0167] For example, a dichroic coating which begins at a pass frequencyof 350 nm has a normal coated tolerance which can vary from between 340and 360 nm, for example. The linearity for any disc is consistent overthe disc. However, the absolute calibration of the disc is notconsistent between different products.

[0168] The discs are calibrated using spectral measurement equipment.Each disc is carefully calibrated. Its values, i.e., position of thedisc relative to passband of the position on the disc, is stored in theassociated memory 470 that is associated with the card. Therefore, eachcolor filter is associated with a stepper motor which is controlled bythe calibrated information.

[0169] A command operation is illustrated in the flowchart of FIG. 4A. Acommand for a certain color combination is made as command 480. Thiscommand is translated by the internal DSP 472 into a pair of pass bandsfor the long and short color wheels 460, 462. This command is thereforetranslated into a desired long passband value and a desired shortpassband value.

[0170] The memory 470 stores a transfer function that represents acalibrated relationship between the position of the wheels and thepassbands. The transfer function can include a variable that acts as amultiplier for scaling the specific disc to a theoretical “ideal” disc.The on-assembly DSP scales each disc according to the variable, so thateach disc operates in the same way.

[0171] These advantages are obtained by maintaining all motors on orassociated with a dedicated assembly as shown in FIG. 4. This allows thecontroller in each card to be preselected with a calibration value thattells that controller the exact value of the color device on its value.The cards stay and are maintained with the assembly. Therefore, eachcard can command exact color values. A command, therefore, for 350 nmcan be adjusted by the calibration to command 350 nm more exactly.

[0172] A similar calibration operation could be used to maintain theaccuracy of any other moving structure.

[0173] As described previously, the system preferably includes an RGBwheel 310 that can be moved in and out of the path of the light beam.The purpose of the RGB wheel is to enable the images to be displayed infull or multi color.

[0174] The inventors recognized that many effects or images can becarried out without this multi color. Moreover, using this RGB wheelalso has a cost: it sacrifices a large percentage of the brightnessbecause of the duty cycle between the three colors. The inventorsrealized that it would be desirable if there was a mechanism foroperating the device without the RGB wheel when monochrome images weredisplayed. This is effected by moving the entire RGB wheel in and out ofthe beam of the lamp.

[0175] The movement operation of this embodiment is made more rapid bybalancing of the weight of the RGB wheel against some other structurewhich is correspondingly moved.

[0176] The movement operation of this embodiment is made easier toachieve and control by balancing the weight of the RGB wheel againstsome other structure which is correspondingly moved.

[0177] A first embodiment of the balance system is shown in FIG. 5. FIG.5 omits the drawing of the mounting bracket. The RGB glass segmentassembly 510 is shown. This includes two, half size red glass segments,a green glass segment and a blue glass segment. The entire device isrotated by a synchronous RGB motor 500.

[0178] The path of the light beam is shown by optical path 502 whichcorresponds to the location where the light beam travels through thefilters.

[0179] The RGB assembly is shown in its outer position in FIG. 5 withthe RGB device positioned outside of the optical path. In this position,the RGB assembly has no effect on the projected light. The RGB assemblyshown in FIG. 5 can be moved into the optical path by pivoting relativeto pivot point 504 along the arrow shown as 506.

[0180] The pivoting operation is carried out by using a motor 510 whichis positioned to act as a counterbalance to the RGB wheel andsynchronous motor. The motor includes a driving element 512, e.g., agear, which positively engages with fixed non-rotatable driving element514, e.g. another gear, to move the assembly. Alternatively, drivingelements 512 and 514, could be pulleys which positively engage eachother by means of an appropriate drive belt or similar. This causes themotor to travel around the driving element.

[0181] In operation, the RGB motor is moved from a neutral positionshown in FIG. 5 to a light altering position where the optical gate isat the location 508 shown in FIG. 5. The motor 510 is rotated to movethe driving element 512 and correspondingly rotate around the fixed, nonrotatable driving element 514. This rotates the entire assembly suchthat the top portion 530 is moved to the right in FIG. 5 while thebottom portion 540 is moved to the left in FIG. 5. The motor 510 islocated within the assembly such that the movement of the motor 510substantially precisely counter-balances the RGB wheel and motor. Thiscounter-balance operation enables the RGB assembly to be rapidly movedwithout being affected by the spatial orientation of the overallfixture.

[0182] A second embodiment of this operation is shown in FIG. 6. Thissecond embodiment of the balancing element is optimized for use inmoving a lens system. The lens 600 is positioned within the optical path602. Lens 600 is positioned on linear bearing 604 to move in a directionsubstantially parallel to the optical path. Movement of the lens eitherin the forward or in the reverse direction, however, can change thebalance of the lighting fixture, thereby effecting overall performanceof pan and tilt functions. The inventors recognized the desirability tomaintain overall balance of the fixture regardless of the lens positionswithin the fixture, thereby maintaining consistent performance of panand tilt functions.

[0183] A driving motor 610 is also mounted on a linear bearing 612.Linear bearing 612 is substantially parallel to the linear bearing 604.The driving motor is attached to a fixed, non movable length of belt 614which is substantially parallel to linear 612. Belt 614 includes teethwhich positively engage with the corresponding teeth on the motorpulley. The motor is also attached to a wire loop 612, which wrapsaround idler pulleys 625, and connects to lens mount 601.

[0184] In operation, the lens and motor move in reverse synchronizationwith each other. Since the belt 614 is fixed, movement of the motormoves the motor relative to the belt. The wire is attached to the motor,so that movement of the motor pulls the lens mount 601 in proportion tothe amount of motor movement. Hence, when the motor moves in thedirection B shown in FIG. 6, the lens correspondingly moves in thedirection A shown in FIG. 6. This maintains a constant center of gravitybetween the motor and lens.

[0185] An alternative embodiment uses either two separate pulleys or atwo stage pulley on the motor. The two pulleys or stages havingdifferent numbers of teeth to each other. One pulley or stage engageswith a fixed non-movable belt to move the motor along the linear bearingas described in the previous embodiment. The other pulley or stagepositively engages with a continuous toothed belt loop which essentiallyreplaces the wire loop as described in the previous embodiment. Thecontinuous belt loop is fixed to only the lens mount so that as themotor rotates and consequently moves along the linear bearing to whichit is mounted. The lens moves proportionally an in a direction relativeto the motor, according to the ratio between the number of teeth on thetwo pulleys or pulley stages on the motor..

[0186] In a particularly preferred embodiment, the motor is selected tobe the same weight as the lens. This can also be operated by choosing alighter motor and adding appropriate weights to the motor to exactlycounter-balance the motor relative to the lens, or if the chosen motoris heavier than the lens, adding weights to the lens mount to achievethe same. Since the same amount of weight is moved in opposingdirections, the motor and lens balancing is the same in any position.

[0187]FIG. 3 shows a block diagram including further detail of thesystem optics. The system uses a segmented retroreflector with a 1,200watt arc bulb. The segmented retroreflector is a design of RadiantImaging, Inc.

[0188] The segmented retroreflector 302 is shown in further detail inFIG. 3A. The device uses an almost elliptical cold mirror reflector 350,along with a special reflecting portion 304 including a series ofretroreflectors which send a portion of the light back into the arc.

[0189] This allows different handling of the three different lightdirections that are output from the bulb 300. A first light, 352, isoutput toward the target, and is allowed to pass unobstructed. A secondlight, such as 354, is produced in the reverse direction, facing awayfrom the target. This light is reflected by the cold mirror reflector350, toward the focal point of the ellipse and against cold mirror 306.A third light, such as 356, is reflected to retroreflectors 302. Eachretroreflector 302 is a section of a sphere that reflects the lightimpinging on that section back to the position of the arc lamp, throughthe position of the arc lamp, to the elliptical reflector 350 andfocused back to the focal point.

[0190] A particularly important part of this invention is its heathandling capability. This is done by a special combination of heataltering elements which remove much of the heat before the light passesto the heat sensitive portions of the system, including the digitalmirror 240.

[0191]FIG. 3B shows an alternative view of the system optics.Retroreflector assembly 302 is shown with its cold reflector andretroreflectors. The output passes to cold mirror 306 which passes mostof the infrared portion of the light, and reflects most of the visibleportion.

[0192] This first filtered light is then passed to a special color crossfader system 308. The color cross fader used herein preferably is of thetype described in U.S. Pat. No. 5,426,576. This device can be used tochange the color of the light.

[0193] A movable red/green/blue (“RGB”) rotating color wheel 310 is alsolocated in series with the color cross fader 308. The pixel by pixelchange of the digital mirror can be synchronized by TI's digital mirrordriving electronics to the movement of the RGB wheel to form amulti-color image. As described above, the attenuation caused by thecolor wheel 310 causes an associated amount of light reduction.Therefore, when a monochrome image is being displayed, the inventorsrecognized that it would be desirable to operate the lighting unitwithout the associated attenuation caused by the RGB wheel.

[0194] The thus filtered and colored light is again reflected by amirror assembly 312. The assembly can include illumination relay 311 andmirror 313, as shown in FIG. 3B.

[0195] The color devices 308 and 310 are between the mirrors 306 and312. This area is preferably an out-of-focus area, so that the color ishomogenized.

[0196] The inventors realized that the digital mirror device has anaspect ratio of 1024:1280≈1.2—that is its length and height are not thesame.

[0197] A third color wheel system 316 is provided at a secondary focusedlocation 314 which forms a second image plane. This third color wheelsystem is a rotatable color filter with discrete color filters. Thosefilters can be similar to the type currently used in the ICON(TM)lighting device. The use of this third color wheel enables the Medusasystem to emulate the color operation of the ICON (TM) system, as wellas to allow additional features.

[0198] The third color wheel system allows the user to select among 8discrete filter elements to be placed on the wheel. The designer canchoose which, if any, are desired. A split color effect can be obtainedby allowing half of each of two filters in the light beam. The wheel canalso include glass elements such as frosted glass or prismatic glass.

[0199] Three different color wheels are provided optically in series—thecolor cross fader 308 is located at unfocused location 307 and theICON(TM) color wheel 316 is located at focused location 314. Any of thethree color altering devices includes a clear location which can beselected, and through which the light will pass unchanged in color. Thisallows any or all of the color altering devices to be inactive so thatlight beam color can be selected by one color changes, both colorchanges or neither color changes.

[0200] For example, color cross fader 308 can be set to clear, allowingcolor altering operation can be done via the ICON(TM) color wheel 316.This enables lighting programs that were previously written for theICON(TM) system to operate the Medusa system without modification.

[0201] The light passing the color wheel is slightly out of focus sincethe focus point is at the color wheel. That light is refracted by a“doublet” lens 318, positioned close to the DMD 240, toward the DMD 240.The light is reflected off of the DMD 240, back through the doublet 318.

[0202] The reflected light from the DMD 240 is coupled to a relay lenssystem 320 which effectively extends the focal length of the system.Another folded cold mirror 322 reflects the light to another relay lens324. Light is finally output by a programmable zoom projection system326.

[0203] The inventors also realized that improved operation of the DMDfor a stage lighting device is obtained when the light is coupled to theDMD with the proper angle of acceptance. The inventors found that theDMD operates best when the light is input with an angle of acceptancelimited to around 28°, more preferably with less than 20°.

[0204] The operation of this system preferably emulates straightprojection optics, with the relay lens forming a 2× multiplier.

Issues with Shadowless Followspot

[0205] One important feature of the present invention is its ability tooperate as a shadowless followspot. The basic characteristics of thisfeature are described in our co-pending application, U.S. patentapplication Ser. No. 08/598,077.

[0206] The inventors of the present invention have realized, however, anumber of issues surrounding accuracy of the shadowless followspot. Oneimportant issue, also recognized in the application 08/598,077, is theaccuracy that would be obtained by operation with zero parallax.

[0207] A first embodiment of the minimized parallax system uses thebasic layout shown in FIG. 3D. A small prism 330 is placed at anoptically insensitive location between the relay lens system 320 and thezoom lens system 326. The prism 330 reflects a portion of the incominglight in a second direction 332. A CCD camera 334 is located in the pathof the reflected information to receive that reflected information via afocusing lens 333. Proper placement of the prism in this location allowsthe prism to reflect light that has a same field of view as isprojected. after the zoom of the prism allows the CCD camera to receiveprecisely the information that is in line with the spotlight andincluding the same field of view as the spotlight. This allows thatcamera to receive precisely what the DMD will project, hence reducingparallax to an almost nonexistent value.

[0208] An important part of the processing of the present invention iscarried out by the Texas Instruments DMD interface board. This boardincludes the DMD device and its associated processing structure. Theboard is laid out and operated using proprietary TI techniques. TI hasindicated that vendors should use the board for their controllingoperation. The board includes the sensitive DMD mounting as part of theboard.

[0209] However, the inventors noticed a problem with using this board ina luminaire. Specifically, the inventors found that the relatively largesize of the board made it difficult to fit properly at an effectivelocation within the luminaire device. The DMD position would beundesirably dictated by the positioning of the board. The inventorsrecognized a need to control the DMD from a location remote from theboard, so that the optical position of the DMD device is totallyseparate from the position of the electrical interface board. Thisallows proper placement of the DMD, taking into account the coolingrequirements and optimal angle of illumination.

[0210] According to the present invention, the inventors used a separateinterface board for the DMD alone which has the effect of remoting theDMD relative to its interface circuitry. A cross section of this boardis shown in FIG. 16. The DMD is shown with bottom electrical contacts.These contacts are usually carefully mated to the corresponding contactson the circuit board. However, the system of the present invention usesan elastomeric interface device to mate between the DMD and a remotecard. The inventors found that the use of the elastomeric interfacedevices facilitates the otherwise difficult DMD mounting.

[0211] The overall colorizing system previously described includes threeparts. A first part is the color cross fading discs 308. These colorcross faders 308 are continuously varying devices. They are best used ata point that is out of focus so that the light can homogenize the colorthereof.

[0212] The RGB wheel is also used at the out of focus location.

[0213] The discrete color wheel 316 is also used as part of the Medusasystem. The discrete color wheel 316 includes a plurality of singlecolor filters and is preferably located at a focused point relative tothe DMD 240.

[0214] One of the important effects capable of being carried out by theICON(TM) is the use of two split colors within the beam. The ICON(TM)color wheel includes a plurality of discrete dichroic filters positionedaround a central hub. The interface between the two discrete colors isplaced at the center of the light beam in order to obtain this effect.This splits the two colors across the beam and provides a focused splitcolor beam.

[0215] Since an important aspect of this new system is the ability toemulate previous generations of luminaires, the use of both in focus andout of focus color wheels enables a maximum number of possibleemulations.

[0216] The Medusa system includes advanced heat reduction mechanisms toimprove the heat handling capability. The production of sufficient lightto illuminate the DMD at stage lighting levels, e.g., >5000 lumens,entails an associated production of huge amounts of heat. As describedabove, a folded cold mirror system is located optically upstream of theDMD to minimize the amount of heat coupled by the light beam towards thedigital mirror. An additional cooling aspect of the present inventionuses a wall of air concept to separate and thermally isolate variouscritical elements from other hot portions of the system. The foldedoptical directs the light beam around or through the wall of air.

[0217] A block diagram of the cooling system is shown in FIG. 8. Thelamp and its reflector are the hottest part of the cooling system. Hencemost of the heat from the system is in the area generally shown as hotspot 800 in FIG. 8. The output from the lamp is coupled to folded coldmirrors to which pass the heat, instead of coupling that heat toward theother components of the system. However, this still results in a hotspot near the heat producing elements which produce the largest amountof heat.

[0218] According to this aspect, a plurality of fans shown as 802, 804and 806 are mounted in a location that surrounds at least a portion ofthe periphery of the hot spot. The fans are located and operate to pusha wall of relatively cool air into the plane defined by the fans. Thewall of air is preferably between the DMD and the heat produced by thehot spot. In addition, although not shown, there may also be a firewallseparating the bulb and reflector assembly from other areas to furtherisolate much of the heat from the hot spot.

[0219] Conceptually the wall of air is shown relative to the DMD andlamp in FIG. 9. FIG. 9 represents a view looking from the side portionin FIG. 8. That side portion shows the end on view of the reflector andthe light following the curved light path to the DMD. The wall of air900 between the reflector, representing the hot spot, and the DMD andeffectively isolates the heat between the two.

[0220] A particularly preferred embodiment uses the folded mirror systemto direct the light path around the wall of air thus formed. If thelight were passed through the air, the light could be distorted by theheat and the like. The light is formed into a folded path that isdirected around the wall to isolate the optical structures from the hotspot.

[0221] In addition, the wall of air is conceptually a source of cool airfor supplying the rest of the system. Many of the items such as thecolor wheel shown in FIG. 9 and electronic assemblies, require a sourceof cool air. In this cooling embodiment, the cool air is obtained byplacing a pick off fan shown as 902 into the cool air and sucking off aportion of that cool air from the wall. Pick off fan 902 couples thecool air to the color wheel area that requires it. Accordingly, the wallof cool air forms essentially a ductless shaft, from which cool air canbe appropriately supplied to those things that require the cooling.

[0222] Accordingly, the wall of cool air forms essentially a ductlessshaft of air, from which cool air can be appropriately supplied to thosethings that require it.

[0223] As a general idea, 20-30 cubic feet per minute over 30 squareinches will provide the necessary amount of air to maintain the wall.

Motor Control Bus

[0224] The motor control bus (“MCB”) is formed by an RS 485 multi-dropbalanced two wire line driver 250, preferably the SN75176, supplied with0V and +5V.

[0225] Data Format. Each byte transferred on the MCB includes: 1 Startbit 8 Data bits 1 Intel address bit (1 signifies the byte is an address,0 that it is not) 2 Stop bits

[0226] The data rate is preferably 250 kbaud, giving a bit time of 4 μs.A single byte is therefore 48 μs long.

[0227] Bus

[0228] The TMS320C80 DSP acts as the master, sending a packet to thefunction drive pcb's every 1 ms. Each transaction has two phases: amaster phase, and a supervisor phase. The master phase sets up theaddress of the function to be communicated. The supervisor phase allowsthe supervisor to determines status and updates the user parameter RAM.

[0229] Data packet specification.

[0230] The timing diagrams for the data transactions on the MCB areincluded as FIGS. 13, 14 and 15.

[0231] The master first sends the address of the function that needs tocommunicated. This is followed by a command byte. If the command is awrite command, it is followed 4 data bytes that depend on the actualcommand that is sent. If the command is a read command, the mastercommand the bus into high impedance state, after sending the command toallow the addressed function to reply. This reply shall start beingtransmitted a maximum of 50 μs from the receipt of the command byte.

[0232] The supervisor continually receives all data packets on the bus.The state of an address byte is recognized from the state of the Inteladdress bit. The supervisor responds by starting a 350 μs timer. Thesupervisor assumes that the master phase is complete after the 350 μs isover, and this starts the supervisor phase.

[0233] The supervisor phase begins by sending a command byte to theaddressed function drive PCB. The command byte is followed by 2 databytes that have a meaning dependent on the actual command byte.

[0234] The addressed function drive PCB replies with a status byte, thatis followed by 2 data bytes that represent the command byte that issent.

[0235] If the 'c80 master is writing to the addressed function drive pcbthe command byte will be followed by up to 4 data bytes, the meaning ofwhich will depend on the particular write command used. If thesupervisor has requested the control on one particular function, thenthe 'c80 master will only transmit the address and null command bytesand leave the bus in a high impedance state to allow the supervisor tosend the data part of the packet during the rest of the 1 mS time slot.b. Read, recognized by having bit 7 set. (i.e. >=128)

[0236] If the 'c80 master is reading from the addressed function drivepcb it will disable the transmitter after sending the command byte toput the bus into a high impedance state to allow the addressed functiondrive pcb to transmit its reply to the 'c80 master. This reply startstransmitting a maximum of 50 us from the receipt of the command byte.

[0237] The supervisor has an address in the same way as the functiondrives, and will be addressed by the 'c80 master at the start of one ofthe 1 ms time slots. The command byte sent by the 'c80 master could be arequest for status from the supervisor. In this case the supervisorreturns a status byte followed by 2 data bytes. This reply starts beingtransmitted a maximum of 50 μs from the receipt of the command byte. Thedata bytes may contain a message to the 'c80 master that the supervisorwishes to obtain control of one or more of the function motors.

[0238] The supervisor returns control to the master by sending anappropriate status byte without the Intel address bit being set.

[0239] If the supervisor has requested control of a particular function,the master responds with a null command following the address of thefunction to be controlled, and a command to place the bus into its highimpedance state. The supervisor recognizes the high impedance state, andresponds with a command and data bytes to control the function. Theformat of the packet as sent is the same as the one that the masterwould have sent.

[0240] The supervisor sends the supervisor command and 2 data bytes.Total control can be commanded in an analogous way. The status byte is abit field with the following flags: Bit Flag Meaning 0 Range error Motoris at end of travel and cannot move the requested position 1 Not readyDuring reset of function 2 Date error Over-run, framing, addressreceived at wrong time 3 Data error Non resetable failure 4 Over currentMotor winding current too high 5 o/t motor Motor too hot 6 o/t heat/sHeatsink too hot

[0241] Parameters Stored In RAM

[0242] The parameters of the individual function drive pcbs are storedin a non-volatile random access memory in an address space that is“off-chip” so they can be changed by the function DSP controlled via theMCB. The stored parameters include: Reset mode (center zero cw or ccw;left or right zero) Reset Sensor (optical/hall or end stop) Rotationallowed (continuous or end stops) PCB Serial No. Assy Serial No. Addressof sub-assy Software version No. Steps of available travelMicro-stepping current profile, or equation of % harmonics Movementprofile

[0243] Byte Definitions

[0244] Address

[0245] This includes the address of the function being addressed duringthe 1 ms time slice, and uses the Intel address bit set to signify thatit is an address byte. The addresses are assigned as follows: FunctionAddress Description 00h Master 01h Pan 02h Tilt 03h RGB in/out 04hShutter 05h Color A (long pass) 06h Color B (short pass) 07h Color C(split color/designer) 08h Zoom 09h Focus 0Ah-0Eh Reserved for futureoptions Ofh Supervisor 10h-FFh Reserved

[0246] Command

[0247] The command byte is either a read byte, which requires theaddressed function to reply with the information specified in thecommand, or a write byte, which allows the transmitting device totransfer some information to the addressed function. Write Commands (msbit clear) Value Command From To 00h Null M/S S/F 01h-0Fh Motion Profile1-16 M/S F 10h Following is master status M S 11h Return control tomaster S M 20h Ignite arc M S 25h Dowse arc M S 70h EEPROM addr and datafollows S F 71h RAM addr and data follows S F 7Dh Reset function card SF 7Eh Stop progaram until go S F 7Fh Go, begin code at addr S F

[0248] Read Commands (ms bit set) Value Command From To 80 Null 81 Sendlast 4 data bytes rx M/S F 82 Send current position M/S F 83 Sendsupervisor status 91 Send current function status S F 92-95h Send parambyte 1-4 S F 95 Send EEPROM data byte S F 96 Send RAM data byte S F 97Send ROM byte S F

[0249] Motor Status

[0250] The motor status is returned by a function after it has beenaddressed by the master and received a command byte from the supervisor.Bit Flag Meaning 0 Range error Motor is at end of trave and cannot moveto requested position 1 Not ready During reset of function 2 Data errorOver-run, framing, address received at wrong time 3 Fatal error Nonresetable failure 4 Over current Motor winding current too high 5 o/tmotor Motor too hot 6 o/t heat/s Heatsink too hot 7 reserved

[0251] Supervisor Status

[0252] The supervisor status is returned by the supervisor after it hasbeen addressed by the master. Value Meaning 00h Null Fch Return controlof following function to master FDh Request control of followingfunction FEh Request control of all functions FFh Reserved

[0253] Position Data

[0254] All position data is preferably 16 bits with the most significantbyte being transmitted first.

[0255] In cases where the data is derived from an 8 bit user value, the8 least significant bits (“lsbs”) of the 16 bit number will be zero.

[0256] Each function drive will have 1 of 4 reset mode parameters storedin the parameter RAM, and the position data sent to the drive isrelative to this mode: Reset Mode Meaning of position data center zerocw or ccw 0000h shall be the center reset position 7FFFh shall be themaximum position, either cw or ccw 8000h shall be the minimum position,either ccw or cw

[0257] left zero or right 0000h shall be the left or right zero position7FFFh shall be the center position FFFFh shall be the right or leftposition

[0258] Timing data

[0259] The most significant byte is transmitted first.

[0260] All positive numbers shall be movement times in 1/60s of asecond, giving a time range of between 0 and 9 minutes 6 seconds.

[0261] All negative numbers are the 1's complement of movement time inseconds, giving a time range of between 0 and 9 hours and 6 minutes.

[0262] For example:

[0263] 003C is a 1 second move

[0264] 5B68h is a 6 minute 30 second move

[0265] 9C4Fh is a 7 hour 5 minute 20 second move

[0266] In summary, each message on the motor control bus includes anaddress of the motor, a command by indicating for example a profile ofthe operation such as trapezoidal or sinusoidal, and four data bytesincluding the end position, the time to reach it and the like. Thesystem preferably talks to one piece of information each onemillisecond.

[0267] Each byte on the motor control bus includes an extra bit. Thatextra bit indicates whether the address bit is or is not using the Intelprotocol. The system used according to this invention is preferably afail safe type system. A command is sent indicating an address of themotor being controlled. The end of this address starts a timer lookingfor a value. That timers preferably 350 ms, and the end of that timerindicates that the command signal is over. The process follows theflowchart of command-delay-motor replies with status. The status caninclude overtemps, motor not ready and data indicative of the motor.Each time the motor is commanded, a command can also be sent to themotor. The master 212 monitors the motor position, since the master 212calculates other motor positions based on the current motor position.The supervisor 230, on the other hand, only cares about motor statussuch as overtemp and the like. The supervisor recognizes every addressand maintains information indicating every address. If the masteraddress is the supervisor, the rest becomes a message. Importantly,since the supervisor is simple electronics, it can still diagnose faultseven once the digital signal processor is no longer capable ofoperation.

[0268] Another operation occurring via the supervisor is asking the DSP212 for control of a certain slave. The master DSP 212 responds bysending the next response with the address of the motor and a blankfollowing the address. The supervisor 230 recognizes this followingblank and sends the whole command which it desires to send. This allowsthe supervisor to control one of the cards via that port.

[0269] The supervisor 230 can also take control of the entire bus 214.This is done by an appropriate command to the master 212, forcing themaster to turn off or reach its high impendance state. At that point thesupervisor carries out all of the commanding. The motors don't know orcare who is doing the commanding, however the supervisor 230 with itslimited electronics capability is not capable of carrying outcomplicated motor control functions.

[0270] The information can be downloaded to the multi-parameter lightingfixture in one of different ways. Preferably, a library of gobo imagesis maintained in some compressed format. The format can be a compressedbitmap such as JPEG image, but more preferably is a vectorized typeimage indicating a mathematical description or geometrical descriptionsuch as so called EPS file. The information is used to define the edgeof the image that is produced, and can be allowed to ignore everythinginside the edge. It can be used for a video source, a shadowless followspot, a gobo image either standard or custom, external video, stillimages, effects such as edge sharping, rotation, pointillism, or crossfade between video feeds.

What is claimed is:
 1. A method of illuminating a stage withsubstantially circular shaped spotlights, comprising: first commanding alight shape altering device to produce a circular shaped beam of lighthaving a profile which is brighter at its center than it is towards itsedges for a spotlight mode; and second commanding the light shapealtering device to produce a circular shaped beam of light with lightwith a substantially uniform brightness profile, for a gobo illuminatingmode.
 2. A method as in claim 1 wherein said profile is a sinusoidalprofile.
 3. A method as in claim 1 wherein a profile of said light has aprofile such that overlapped light beams produce an amount of lightwhich is within 20% of an amount of light produced by the center of anonoverlapped light.
 4. A method of calibrated operation of a lightingdevice, comprising: determining a characteristic of a movable lightingdevice control element, said movable lighting device control elementincluding a capability of moving at least one element in said movablelighting control device from one position to another position;determining a specific moving characteristic of positions of saidmovable lighting device as a function of control signal, as calibratinginformation; storing said specific moving characteristic as a calibratedvalue for said movable lighting device; receiving a command for saidmovable lighting device to move said movable lighting device to aspecific position; accessing said specific moving characteristic todetermine said calibrated value to thereby operate using a calibratedoperation.
 5. A method as in claim 4 wherein said movable lightingdevice control element is a color changer and said calibration is acalibrated position of said color changer.
 6. A method as in claim 4wherein said movable lighting device control element is a stepper motorand said position is a calibrated position of said stepper motor.
 7. Amethod as in claim 4 wherein said device is a motor movement device andsaid position is a position of the motor device that is driven by saidmotor movement device.
 8. A stage lighting apparatus, comprising: alight beam producing element, producing a beam of light; a motor controldevice, having an operative portion located to alter some aspect of saidbeam of light; a memory, associated with said motor control device,storing some value which is uniquely associated with said motor controldevice to which the memory is associated; and a command element, readingout a value from said memory, said value indicating control of saidmotor control device, and operating to control said device to saidcalibrated position based on said read out control value.
 9. Anapparatus as in claim 8 wherein said motor control device is a motordriven color changer.
 10. An apparatus as in claim 8 wherein said motorcontrol device is a pan and tilt motor to change a projected position ofsaid beam of light.
 11. A balanced optical system, comprising: a sourceof light, producing an output light beam; a movable optical elementmovable between positions to change some aspect of said light beam; anda counterbalance, operatively coupled to said movable optical element,in a way such that said counterbalance is automatically moves when saidoptical element is moved, and operating to counterbalance movement ofsaid movable optical element such that said movement of said movableoptical element produces no change in balance to said balanced opticalsystem.
 12. A system as in claim 11 wherein said counterbalance is amotor which drives said movable optical element, said motor weighingsubstantially a same amount as said movable optical element.
 13. Anapparatus as in claim 11 wherein said movable optical element is an RGBwheel.
 14. An apparatus as in claim 11 wherein said movable opticalelement is a lens.
 15. An apparatus as in claim 11 further comprising alinear block operating to counterbalance said motor.
 16. An apparatus asin claim 11 further comprising a rotation device operating tocounterbalance said motor.
 17. A method of operating a stage lightingsystem with balanced operation, comprising: providing a beam of lightalong an optical pathway; providing an optical light changing element insaid beam of light, said optical light changing element being movable inposition to change some aspect of said beam of light; providing a motorto move said optical light changing element between a first positionwhere the optical element has a first effect on the light and a secondposition where the optical element has a second effect on the lightdifferent than said first effect; and moving the motor and the opticalelement in reverse synchronization with another in a way such that acenter of gravity between said motor and said optical element stays thesame at any position of the combination of the motor and the opticalelement.
 18. A wireless communication system for a stage lightingdevice, comprising: a stage lighting luminaire, including a processorcontrolling operations of the luminaire, and including a wireless dataport through which information can be received and sent to and from theluminaire; and a remote computer device, including a wireless interface,and operating to communicate with said wireless data port on said stagelighting luminaire, said remote computer device receiving an outputsignal in a format which represents a readable format, and convertingsaid output signal to said readable format.